Steam boiler



Patented Felt. 11, 1936 STEAM BOILER Fred H. Daniels, Worcester, Mass,assignor to Riley Stoker Corporation, Worcester, Mass., a. corporationof Massachusetts Application September 13, 1933, Serial No. 689,296

5 Claims.

This invention relates to steam boilers, and more particularly towater-tube boilers having a transverse horizontal water drum whichserves to connect a lower bank of tubes to an upper bank.

When boilers of this type are operated at high ratings, and particularlywhen water walls are provided which discharge into the drum, there is atendency for steam to accumulate in the upper portion of the drum andprevent water from entering the tubes in the upper part of the uppertube bank. This condition is aggravated when side water walls areprovided, since they cause a concentration of steam in the end portionsof the drum. As a result, the tubes located in the upper part of theupper tube bank and near the side walls may receive insufficient waterto protect them from overheating.

It is accordingly one object of the present invention to overcome thesedifficulties and to provide a construction which will decrease theconcentration of steam in the upper portion of the drum and thus allowmore water to enter the tubes of the upper bank.

It is a further object of the invention to provide means fordistributing the steam more uniformly lengthwise of the drum when sidewater walls are connected to the ends of the drum.

With these and other objects in view, as will be apparent to thoseskilled in the art, the invention resides in the combination of partsset forth in the specification and covered by the claims appendedhereto.

Referring to the drawing illustrating one embodiment of the invention,and in which like reference numerals indicate like parts,

Fig. 1 is a vertical longitudinal section through a steam boiler andfurnace, the section being taken on the line ll of Fig. 2;

Fig. 2 is a section on the line 22 of Fig. 1; and

Fig. 3 is a section on the line 3-3 of Fig. 2.

In the drawing I have illustrated a steam boiler comprising a rear lowerwater drum ID, a front upper water drum 1 I, and a steam and water druml 2 located above the drum HI. These drums are arranged with their axesparallel and horizontal. The drum I is connected to the drum H by a bankof upwardly and forwardly sloping water tubes l4, and the drum II isconnected to the drum l2 by a bank of upwardly and rearwardly slopingwater tubes I5. The drums l0 and l 2 are connected by a bank ofsubstantially vertical water tubes 16. A steam drum I1 is mounted abovethe front water drum l I, and the drums l2 and ii are connected by a rowof steam tubes .I 8 which support refractory material l9 ar ranged toform a roof for the boiler.

Walls 2 l are arranged to provide a furnace chamber 22 beneath the lowertube bank l4, direct hot gases from the furnac across the tube banks l4,l and I6 let 24.

In order to protect the furnace and baflles 23 e successively to a gasoutwalls and at the same time generate steam by the absorption ofradiant heat and thus prevent excessive furnace temperatures, Ipreferably provide a row of vertical water wall tubes 26 at each side ofthe furnace.

These tubes extend between lower headers 2'! and upper headers 28. Thelower headers 21 are supplied with water from the drum I0 by means ofdown-comer tubes 30 leading from the drum to the rear portions of theheaders.

The rear portions of the upper headers 28 are connected to the steam andwater drum I2 by up-comer tubes 3|, and

the front portions of the headers 28 are connected to the front waterdrum H by up-comer tube s 32. At the front of the furnace I provide arow of vertical water wall tubes 34 which extend between the drum I anda horizontal header 35.

This header is supplied with water from the drum I l by means of a rowof down-comer tubes 36 leading from the drum to the header and locatedoutside of the tubes 34.

The down-comer tubes 36 are protected from the heat by the refractorymaterial of the furnace wall.

With the construction as so far described, there will be a large amountof steam discharged into the drum II, and this steam wii I tend toaccumulate in the upper portion of the drum and prevent the entrance ofwater into the tubes of the bank l5. Moreover, this steam concentrationwhich would normally be released in the: drum ll, directly to the tubesin the upper portion of the tube bank l5. For this purpose I have shownapartition plate 38 mounted inside the drum H and cooperating with thefront portion of the drum wall to form a passage 39 leading from thefront water wall tubes 34 to the upper row of tubes in the tube bank l5.

This construction greatly reduces the quantity of steam released in thedrum, since the tubes 34 are exposed to the radiant heat of the furnaceand hence generate steam at a very high rate.

In order that the circulation through the tubes 34 may be maintained,means is provided to deliver water into the upper ends of the down-comertubes 36 from the main portion of the drum. In the preferredconstruction the tubes 36 are extended inwardly through the partition 38so that water may enter these tubes freely.

Near each end of the drum II the partition plate 38 is preferablyextended rearwardly, as indicated at 48, to enclose the upper ends ofthe up-comer tubes 32 and thus compel the steam delivered by these tubesto flow through the passage 39. Not only does this still furtherdecrease the amount of steam liberation in the drum, but it also resultsin a substantially uniform distribution of the steam throughout thelength of the drum.

The operation of the invention will now be apparent from the. abovedisclosure. The furnace 22 is fired in any suitable manner, and the hotgases flow across the tube banks [4, l5 and I6 to the gas outlet 24.Water circulates downwardly in the tube bank l6 and upwardly in the tubebanks l4 and I5. Steam which is generated in the various tubes isfinally released in the drum l2 and flows through the tubes l8 to thedrum H, from which it is withdrawn for use. Water" flows from the druml8 downwardly through the tubes 39 to the header 27 and thence upwardlythrough the side water wall tubes 26, the headers 28, and the up-comertubes 3! and 32. Water flows from the main portion of the drum lldownwardly through the tubes 36 to the header 35 and thence upwardlythrough the front water wall tubes 34. The steam and water mixturedischarged from the up-comer tubes 32 and the water wall tubes 34 fiowsthrough the passage 39 and thence through the upper row of tubes in thetube bank 5 to the drum l2. An adequate circulation is thus maintainedin this tube row. At the same time entrance of sufficient water into theremaining tubes of the bank I5 is assured, because of the greatlyreduced steam liberation in the drum ll and the equalization of thesteam liberation longitudinally of the drum. As a result, all the tubesare protected against the possibility of overheating, and the boiler canbe operated at very high steaming rates without danger.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patcut is:

1. A steam boiler comprising a transverse horizontal water drum, a lowerbank of tubes connected to the drum and extending rearwardly anddownwardly therefrom, an upper bank of tubes connected to the drumandextending rearwardly and upwardly therefrom, a furnace wall at thefront of the drum, water wall tubes associated with the wall andconnected to the drum, a partition mounted within the drum andcooperating with the front wall of the drum to form a passage leadingfrom the water wall tubes to tubes in the upper portion of the uppertube bank, and downccmer tubes arranged to supply water from the mainportion of the drum to the water wall tubes.

2. A steam boiler comprising a transverse horizontal water drum, a lowerbank of tubes connected to the drum and extending rearwardly anddownwardly therefrom, an upper bank of tubes connected to the drum andextending rearwardly and upwardly therefrom, a furnace wall at the frontof the drum, a row of substantially vertical water wall tubes associatedwith the wall and connected at their upper ends to the drum, a partitionmounted within the drum and cooperating with the front wall of the drumto form a passage leading from the water wall tubes to tubes in theupper portion of the upper tube bank, a header at the lower ends of thewater wall tubes, and a row of substantially vertical downcomer tubeslocated in front of the water wall tubes and connecting the drum withthe header, the upper ends of the do-wncomer tubes extending through thepartition into communication with the main portion of the drum.

3.- A steam boiler comprising a transverse horizontal water drum, alower bank of tubes connected to the drum, an upper bank of tubes connected to the drum, walls forming a furnace chamber beneath the lowertube bank, water wall tubes associated with the side walls of thefurnace chamber and arranged to discharge steam 1.;

and water into the end portions of the drum, and means to conduct saidsteam and water into certain of the tubes of the upper tube bank withoutfirst mingling the steam with steam discharged into the drums by thetubes of the lower tube bank. I

4. A steam boiler comprising a transverse horizontal water drum, a lowerbank of tubes connected to the drum, an upper bank of tubes connected tothe drum, walls forming a furnace chamber beneath the lower tube bank,water wall tubes associated with the side walls of the furnace chamberand arranged to discharge steam and water into the end portions of thedrum, and a partition mounted within the drum and cooperating with thewall of the drum to form a passage which serves to conduct said steamand water to tubes in the upper portion of the upper tube bank withoutfirst mingling the steam with steam discharged into the drum by thetubes of the lower tube bank.

5. A steam boiler comprising a transverse horizontal water drum, a lowerbank of tubes connected to the drum and extending rearwardly anddownwardly therefrom, an upper bank of tubes connected to the drum andextending rearwardly and upwardly therefrom, walls forming a furnacechamber beneath the lower tube bank, water Wall tubes associated withthe side-walls of the furnace and arranged to discharge steam and waterinto the end portions of the-drum, water wall tubes associated with thefront wall of the furnace and connected attheir upper ends to the drum,and a partition mounted within the drum and cooperating with the wallthereof to' fo-rm a passage which serves to conduct steam and water fromthe side water wall tubesand the front water wall tubes to tubes in theupper portion of the upper tube bank without first mingling the steamwith steam discharged into the drum by the tubes of the lower tube bank.

FRED H. DANIELS.

